Plow-point



(No odel.)

A DOW.

PLOW POINT.

No. 575,666. Pat e nted Jan. 19, 1897.

C WI/110% Best Avaaaets GQPY v} UNiTnD States PATENT @rricn.

. GIL \TRLES LA DO\V, OF ALBANY, NE\V YORK.

PLOW-POINT.

SPECIFICATION forming part of Letters Patent No. 575,666, dated January19, 1897.

Application filed November 21, 1896. Serial No. 612,921. No modell ToctZZ 107mm 2'15 may concern:

Be it known thatI, CHARLES LA DOW, a citizen of the United States,residing at- Albany, in the county of Albany and State of New York, haveinvented certain new and useful Im rovemcnts in Ilow-Poin is of whichthe following is a specification.

My invention consists in a plow-point of novel construction, ashereinafter fully set forth.

The purposes of my invention are to increase the strength ofplow-points, to permit the same to be made longer and thinner thanheretofore, and to cause one face or a portion of one face to wear awaymore rapidly than the other face or portions, and thereby to maintain athin sharp edge.

Figure l is a top plan or face view of a plowshare provided with myimproved point; Fig. 2, aperspective view of a wrought-metal strip, suchas is incorporated into the point; Fig. 3, sectional view illustratingthe mc'thod of applying said strip and incorporating it into the pointof the finished share; Fig. 4, a perspective view of a plow-point,showing the wrought-metal strip secured in place by studs or rivetsformed in casting the share; Figs. 5 and 0, cross-sections of theplowpoint, Fig. 5 showing it as it appears when first made and Fig. '6illustrating the manner in which it wears away.

At the present time plowshares are universally cast, and usuallywithfthe points as an integral portion thereof. For the purpose ofrendering the points more durable and thus prolonging the life of theshare it is customary to chill the point by placing'within the mold ametal body of sufficient size to preclude its becoming heated to anyconsiderable extent by the molten metal, this cold body serving to chilland set the molten metal quickly and to render very hard that portion ofthe casting which comes in contact with the chill. It is essential tothe attainment of satisfactory results in the matter of chilling that aspecial grade of iron be used, some varieties becoming .so exceedinglybrittle under chilling as to be useless and incapable of withstandingthe strains to which a plow-point is subjected, while others cannot behardened at all by chilling. It is found in practice that when metal ofthe proper grade or quality for the production of a properly-chilledplow-point is used the chilling elfeet and consequent hardening extendsentirely through the point from face to face, and consequently the upperface of the plowpoint, which is farthest from the chill in the mold, ismade practically if not quite as hard as its lower face. This is duelargely to the fact that the pointis relatively thin and that the metalwhich forms it flows from the rearward end of the mold over the coldbottom thereof before reaching the portion of the mold in which thepoint is cast, and being at most a small body does not possesssuflicient heat to overcome the effects of'the relatively large mass ofcold iron of the chill. Itis desirable, however, to cause one face ofthe point to wear away more rapidly than the other in order that it mayautomatically thin down toward the extreme point or entering edge and bealways in condition readily to enter the ground or find its way into andthrough the soil in which the plow is used.

My invention aims to secure this result,together with other desirablequalities above indicated; and to this end it consists in placing withinthe mold a strip or body of soft metal, preferably iron or steel, insuch position that it shall be incorporated into the point cast thereinat that side or face of the point opposite that cast against the chill.It

being the usual practice to chill the lower face of the point, the stripabove referred to is placed in position to constitute a part of theupper face of the point, or, in other words, as the share is cast upsidedown, with the chill at the upper side of the mold cavity or matrix, thewrought-metal stripis placed at the bottom of said cavity. This will bebetter understood upon referring to the drawings, in which- A indicatesa plowshare, 13 its point, and C the wrought-metal strip incorporated inthe upper face of said point. The strip 0 as it appears before suchincorporation is shown in Fig. 2, and in Fig. 3 it is shown lying uponthe bottom of the matrix orcast space of the mold D, directly beneaththat portion of the chill E which overlies the point B of the share A.

dross, &c., to work back toward the heel of the plowshare or to a pointWhere its possible incorporation into the casting would be of slightconsequence. It will be seen that if the strip C be thus placed in themold D, the chill E be placed in position, and the cope or upper sectionof the mold be applied to the drag, so that the parts occupy thepositions indicated in Fig. 3, the molten metal entering the mold willflow to the point C, the mouth of the sprue-hole being materially higherthan said point, and while the upper surface of said metal comes intocontact with chill E and is suddenlycooled and made quite hard the lowerportion of the metal, forming the point B, flows around the sides of thestrip 0, which are preferably beveled, as in Figs. 2, 5, and 6, andfirmlyincorporates said strip into the casting. a

Previous to its being placed in the mold the strip 0 is by preferencetinned, and this is usually done at the place of manufacture of saidstrips,which may be distinct from that at which the shares are cast. Thepurposes'of thus tinning the strips 0 are, first, to prevent rusting inhandling, or while being shipped or stored, and, secondly, to enable themolten metal portion to unite with the wrought metal of the strip, thetin serving as a solder or as a flux and facilitating the fusion of theedges and surface of the strip and its perfect union with the metal ofthe casting. As is Well understood, the wrought-metal strip cannot bechilled, and consequently, although the chilling etfect may extendentirely through that portion of the plow-point between the strip G andthe chill E, there will always be in the finished point a face ofrelatively soft metal as thick as the strip 0.

When the iron in the ladle begins to cool or become dull, it may happenthat it will not possess sufiicient heat to effect a fusion of the edgesand surface of the strip 0 with which it comes into contact, and that.consequently, although the cast metal may, by reason of the beveling ofthe edges of the strip, hold said strip against play or movement, theremay be under severe strains a tendency to spring or bend the point andthereby to move or slide the strip longitudinally in its seat. Toprevent this, I may form slight indentations a in the under face of thestrip 0, which may be conveniently done with a prick-punch, or Iotherwise roughen the face against which the molten metal is brought, sothat when the casting is formed the two contacting surfaces shallinterlock sufficiently to prevent the longitudinal movement noted.

InFig. 2 I have shown the edges of the stri p C beveled, so that thecast metal shall overlap the edges, as in Figs. 5 and 6. This provision,together with the shrinkage of the metal in cooling, causes the strip tobe very firmly bound and held in place, even if there be no fusion andno soldering efiect, but it may in some cases be desirable to perforatethe strip 0 in the manner indicated in Fig. 4 and per- ;rnit the moltenmetal to flow through the per-- 1), which willserve the double purposeof securing the strip in position and. preventing play in any direction.The perforations should be countersunk, asindicated in Fig. 4.

As indicated in the several figures, the strip 0 is somewhat narrowerthan the plow-point B, and is so made for the purpose of affording asuflicient body of cast metal at each side to firmly clasp and retainthe strip 0, and also to give to the upper face of "the point differentdegrees of hardness at its middle and side portions. The effect of thechill being carried entirely through the cast portion of the point itwill be seen thatthe side portions 0 hard, while the intervening portionof said face will be soft,'and as a consequehce the upper face will,when the point is subjected to the wearing or scouring action of thesoil, wear away more rapidly at the middle than at the sides,-producingaconcave surface, as indicated in Fig. 6. This is quite desirable point.

It will be seen from the foregoing description that I not only vastlyincrease the tensile strength of the point and its capacity to resistbreaking strains by reason of the in --the upper face to wear away morerapidly than the lower face, to take a concave form, and since the'wearis most rapid at the extreme forward end, to wear thin at the point andpreserve at all times a sharp entering edge, which conduces greatly tothe efficient working of the plow. Under the ordinary construction ofplowpoints the forward corners of the points wear away more rapidly thanthe intervening portion and thus produce a taperingor rounded nose orend, which does not preserve its course or direction as Well as thesquare-ended point first formed. Under my plan, how ever, and owing tothe wearing away of the softer central portion more readily than that ateither side of it, there is a sort of compensation for the greaterfriction to which the corners are subjected, and consequently a moreuniform receding of the-point across its .lentire width. I

It is obvious that'the form of the strip and the material of which it ismade may vary and that more than one strip may be used.-

and the cast metal may cover its outer face in whole or in part. In suchcase the thin forations and form fastening studs or rivets,

of the'upper face of the point B will be quite in practice and adds tothe eiiiciency of the troduction of wrought metal, but I also cause filmof metal over the outer face will partly So, too, the position of thestrip may vary wear and partly break away in use and thus gradually thinthe point. In Whatever position the wrought-metal strip be placed or--whatever be its cross-section it will mateg'rially aid in strengtheningthe plow-point.

' stand such breaking strains.

It is found that by reason of the great tensile strength afforded by thewrought-metal strip it is perfectly feasible to make the plowpointthinner than heretofore without reducin g its strength or capacity towithstand transverse strains. In fact, it is possible to make the pointthinner than heretofore and still have greater strength or capacity towith- It will 'therefore be seen that I am enabled to produce in thefirst instance and to maintain in use a thinner and sharper point thanhas heretofore been practicable, and consequently to furnish animplement which may be forced through the soil more readily than thoseheretofore in use.

Having thus described my invention, what I claim isp 1. As a new articleof manufacture, a plowshare having a castmetal point integral therewith,and a wrought-metal strip cast in the metal of the point only,substantially as set forth.

2. A 'cast-metal plowpoint having a wrought-metal strip embedded in oneof its faces, substantially as shown and described.

3. A cast-metal plow-point having one face provided with a wrought-metalstrip extending lengthwise thereof, and having cast-metal borders atopposite sides of said strip.

4. A cast metal plowpoint having a wrought-metal strip embedded in oneface, and retained therein by the castmetal overlapping its edges.

5. A cast -.metal plow point having a wrought-metal strip embedded inone face and held in position by projecting portions of the cast metalentering cavities or openings in the wrought metal.

6. A cast-metal plow-point having a wrought-metal strip embedded in oneface; the strip being tinned roughened, or indented vto cause the castmetal to engage with and prevent it from moving relatively thereto.

7. A cast-metal plow-point combined with a strip of soft metalconforming to the contour of the face of the point and cast therein.

In witness whereof I hereunto set my hand in the presence of twowitnesses.

' CHARLES LA DOW. Witnesses:

D. E. BURDINE, HORACE A. DODGE.

